Lathe for turning irregular shapes.



No. 853,987. PATENTED MAY 21, 1907. M. H. LYONS.

LATHE FOR TURNING IRREGULAR SHAPES.

APPLICATION FILED SEPT. 18,1905. 7

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. PATENTED MAY 21, 1907. A -M. H. LYON Sr v LATHE FOR TURNING IRREGULAR SHAPES.

APPLICATION TILED SEPT. 18,1905.

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UNITED STATES PATENT OFFICE.

LATHE FOR TURNING IRREGULAR SHAPES.

T0 at whom, it may concern.-

Be it known that I, MronAEL H. LYoNs, a citizen of the United States, residing at Brockton, in the county of Plymouth and State of Massachusetts, have invented an Improvement in Lathes for Turning Irregular Shapes, of which the following description, in connection with the accompanying draw-. ings, is a specification, like letters on the drawings representing like parts.

While my invention is adapted to turning various kinds of irregular shapes, it is primarily intended for improving last lathes. As is well known, lasts are very peculiar in their lines and diflicult to turn in the various sizes without distortion. In fact, it has been so universally recognized that distortion must take place, that model makers frequently make the model with this end in view and when fine results are required they do not permit all the sizes to be enlarged from the same model, but require several sizes of models.

My invention aims to make the lathe more accurate and less liable to distort, as well as to improve the simplicity and free running of the lathe. v

The constructional details of my invention will be pointed out in the course of the following description, reference being had to the accompanying drawings in which I have illustrated a preferred embodiment of my invention.

In the drawings, Figure 1 is a right-hand end elevation of one embodiment of my invention; Fig. 2 is a perspective view of the ways and main frame thereof; and Fig. 3 is a back side elevation.

I have purposely omitted as many of the complicated portions of the lathe as possible, not relating directly to my invention, in order that the latter may be more clearly understood, and I will. confine my description to those parts of the lathe directly comprising my improvements.

My improvements relate to the so-called swing frame or work frame. This has heretofore been pivoted, sometimes at the top and sometimes at the bottom of the frame adjacent the floor, extending up in front of the cutters and pattern-wheel or guide-wheel, where it has been provided with suitable dogs or chucks, driving shaft and gears, for supporting and rotating the model and block to be turned. The result has been that-the movement was more or less unoer- Specification of Letters Patent.

Patented May 21, 1907.

Application filed September 18. 1905. Serial No. 278,892.

tain, the operation ponderous, and because of the arc-movement, the larger portions of the block would be cut with relation to a different angle from the center of the block from the smaller portions of the block, besides other more or less complicated distortions and undesirable results. Also in this type of lathe there is a strong tendency to undue vibration which distorts and renders uncertain the results of the turning. Accordingly, I have provided a swing frame which moves in a rectilinear path, and eliminates entirely the swinging or arc-movement, as well as all twisting and improper yielding movement and have so arranged the general construction that all the work is done within the supporting lines of the guide ways, having provided opposite widely separated tracks or guide ways carried by the main frame at its opposite ends and sides on which are mounted the working parts of the machine so positioned and constructed that all the work is done in the space above, and between the vertical planes of, said ways. This gives great stability and tends to eliminate the vibration referred to.

On the ends of a suitable main frame 1 I provide transverse rods or ways 2 secured at their ends in brackets 3, and on these ways I mount end-carriages 4 having widely-separated, flanged wheels or rollers 5, 6, and to the face of the carriages 4 I rigidly secure a thrust bar 7 provided with an upper track 8 and a lower bar and track 9, and on these tracks 8, 9 are adjustably mounted the usual saddle or head stock 10 and saddle or tail stock 11, the latter being provided with a toe-dog 12 and operating wheel 13, and the former having the usual short shaft 14 provided at one end with a toe-dog 15 forthe model, and at the other end with a chuck 16 for the block. Co-operating with these is the drive-shaft 17. The "swing frame or work frame consists of the end carriages, upper and lower tracks and the adjustable head stock and tail stock. At their opposite ends the carriages 4' are connected by opposite arms 18 to rocker arms 19 fast at the opposite ends of a rocker shaft 20 provided with heavy coiled springs 21, 22 of a large number of turns each, fast at one end 23 to the frame of the machine, and adjustably secured at their other ends by collars 24 to the rocker shaft 20, for maintaining the swing frame under constant pull forward, thereby holding the model unremittingly against the patternwheel or guide-wheel 25 and causing the block to be correspondingly shaped by the cutter 26. By providing the rocker shaft with its opposite arms 19 and the oppositely coiled springs 21, 22 for giving the opposite ends of said shaftuniform and constant tendency to turn over to the right, Fig. 1, still further means for preventing vibration and uncertainty of movement is provided, and the parts are kept in perfect balance at all times and equally at both ends.

The cutter and guide-wheel are journaled in carriages 27, 28 slidingly mounted on widely separated rods or ways 29, 30 fast respectively in the front side andrear side of the frame 1 along which ways said carriages 27, 28 are automatically fed by a usual feeding mechanism (not shown). As already stated, it will be understood that suitable driving mechanism is employed for operating the various parts the same as usual in this class of lathes.

To secure the necessary positive and uniform rotation of the work without interfering with the free travel of the frame on the tracks 2, I provide the sprocket wheel 31 with a chain 32 passing over a driven sprocket 33 and held constantly taut under uniform ten sion by an idler 34" at the free end of an arm 35 held downward by a spring 36 at such an angle, as shown, that there is a constant strong tendency to tighten the chain, the latter traveling downward in its contact with the idler.

In operation, the guide wheel 25, ressing against the model, causes the swing rame to slide in a straight line backward and forward with relation to the rapidly rotating cutter 26, which, therefore, correspondingly cuts the block. The rectilinear movement of the swing frame maintains absolute precision and uniformity of position irrespective of the size or shape of the model, and, moreover, as the bearings 5, 6 are widely separated and only a short distance from the region of cutting, which lies vertically between them, the result is that I secure great rigidity and an entire absence of twisting and spring. The cutting thereof, and all strain, is directly downward and between the two rolls or bearings 5, 6. Everything is directly under the immediate inspection of the operator as he stands Watching the work, and the mechanism is removed as far as possible from the base of the machine where the chips and debris always accumulate. Also I secure decided advantage by the tension arrangement provided by therocker shaft 20 and springs 21, as thereby I am enabled to secure constancy of tension irrespective of the size of the model. By having the coiled springs, and making them of considerable length, there is no appreciable change of tension between the extreme outward and inward movements of the swing frame, and the rebound and uncertainty which have always attended the use of weights is eliminated. I might explain further, as to this point, that, for instance, when turning a last having a large variation in the shapewhere the spring of the last comes, a sudden drop or inward movement of the swing frame has heretofore caused a rebound of the weights employed, thereby momentarily relieving the tension, so that a lack of accuracy and uniformity in turning such lasts has resulted. By my construction, however, I have succeeded in entirely eliminating this inaccuracy, as there is scarcely any change in tension even in turning such a last as the one mentioned. By having two springs, I am enabled to adjust them independently and very easily to suit the requirements of the machine, and I am permitted to secure extreme accuracy and delicacy of adjustment and perfect balance or uniformity of adjustment at both ends, even though the machine is run at high speed. Also it is not necessary to wind the two springs as tight as would be the case with one spring and they can be placed at the opposite ends of the shaft where they are required for the greatest efficiency and accuracy.v

It will be understood that I am not limited to the constructional details of my invention in all cases, as many variations and substitutions may be resorted to without departing from the spirit and scope of my invention.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a lathe of the kind described, a main frame, parallel longitudinal ways at the opposite sides of the main frame, parallel trans verse ways at the opposite ends of the main frame above said longitudinal ways, a guide wheel and cutting means slidingly mounted in axial alinement with each other on said longitudinal ways, and a work frame mounted on said transverse ways to travel above and between said longitudinal ways, provided with means for supporting a model opposite said guide wheel, and for supporting the work to be turned opposite said cutting means- 2. In a lathe of the kind described, a main frame, a guide wheel, a rotary cutter, transverse horizontal ways on the main frame, a work frame provided with opposite carriages having at their lower edges widely separated supporting wheels traveling 011 said ways and means carried by said work frame at the front side of the carriages above and between said supporting wheels for supporting a model opposite said guide wheel and for supporting the work to be turned by said cutting means.

3. In a lathe of the kind described, a main frame, parallel longitudinal ways at the opposite sides of said frame and parallel transverse ways at the opposite ends of said frame,

turned opposite said cutting means.

4. In a lathe of the kind described, a main frame, provided adjacent its front side andv rear side with longitudinal rods or ways, and

adjacent its opposite ends above said longitudinal rods or ways with parallel transverse rods or ways, a guide wheel and carriage and a rotary cutter and carriage mounted to move on said longitudinal rods or ways, a longitudinal frame having end carriages mounted to. move transversely on said end rods or ways between said longitudinal rods or ways, means carried by said longitudinal frame for supporting a model opposite said guide wheel and for supporting work to be turned opposite said cutter, a longitudinal rocker shaft adjacent the rear side of the machine, rocker arms fast on the opposite ends of said shaft and connected to said longitudinal frame adjacent the opposite ends thereof, and springs coiled in opposite directions respectively around the opposite ends of said rocker shaft, each spring being se cured at one end to a fixed part of the frame and adjustably secured at its other end to the rocker shaft in such relation thereto and of such length of coils as to bring a uniform rearward pull at all times upon said longitudinal frame.

5. In a lathe of the kind described, a guide wheel, a cutter, a frame provided with means for supporting a model opposite said guide wheel and for supporting the work to be turned opposite said cutting means and constructed and arranged to move toward and from said guide wheel and cutting means,

,nected to said frame adjacent the opposite ends thereof respectively, and springs coiled in opposite directions respectively around the oppositeends of said rocker shaft, each spring being secured at one end to a fixed part of the frame and adjustably secured at its other end to the rocker shaft in such rela tion thereto and of such length of coils as to bring a uniform rearward pull at all times upon said longitudinal frame.

6. In a lathe of the kind described, a guide wheel, a cutter, a frame provided with means for supporting a model opposite said guide wheel and for supporting the work to be turned opposite said cutting means, said frame having end carriages provided at their lower edges with supporting wheels spaced far apart and at either side of said guide wheel and cutting means to give stability of position to the latter, transverse ways at the opposite ends of the machine for receiving said guide wheels of the respective carriages, a longitudinal rocker shaft, rocker arms fast at the opposite ends of said shaft and connected to said end carriages approximately in line with the wheels at thelower edges thereof for giving additional stability of position and movement to the frame, and springs coiled in opposite directions respectively around the opposite ends of said rocker shaft,

each spring being secured at one end to a fixed part of the frameand adjustably secured at its other end to the rocker shaft in such relation thereto and of such length of coils as to bring a uniform rearward pull at all times upon said longitudinal frame.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

MICHAEL H. LYONS.

Witnesses:

Gno. H. MAXWELL, ALICE M. LYONs. 

